1. Field of the Invention
The present invention to a disk cartridge for rotatively accommodating a disc recording medium, such as a magnetic disk.
2. Description of Related Art
Hitherto, a hard disk has been used to record/reproduce a data signal, which must be processed by a computer, and an information signal of a program for operating the computer. The information signal is read/written to and from the hard disk by a magnetic head for scanning the hard disk.
The hard disk includes a removal disk in the category thereof which is structured to be detachable from a recording/reproducing portion of the computer. The removable hard disk enables the capacity of the information recording/reproducing unit of a computer to be enlarged.
To make the hard disk to be detachable and portable, the hard disk is accommodated in a disk cartridge. The disk cartridge includes a cartridge body having a disk accommodating portion in which the hard disk is rotatively accommodate, the cartridge body having a recording/reproducing opening formed to permit, for example, a magnetic head of the recording/reproducing unit to be inserted.
However, if foreign matter, such as dust, is introduced through the recording/reproducing opening in the disk cartridge, dust is allowed to adhere to the accommodated hard disk. Thus, there arises a problem in that information signals recorded on the hard disk deteriorates.
To overcome the above-mentioned problem, the disk cartridge has a shutter for opening/closing the recording/reproducing opening so that the disk cartridge is able to close the recording/reproducing opening when the hard disk is not used.
As a disk cartridge of a type having a shutter, a disk cartridge 201 of a type for rotatively accommodating a shutter 203, as shown in FIG. 1, has been known. The disk cartridge 201 is structured such that the shutter 203 is, as shown in FIG. 2, rotated into the cartridge body 202 in which the magnetic disk 205 is accommodated when the magnetic head is inserted into the cartridge body 202 which accommodates the magnetic disk 205. Thus, the recording/reproducing opening 204 is opened.
However, the disk cartridge 201 must have, in the cartridge body 202 thereof, a space for permitting the shutter 203 to be retracted.
That is, the disk cartridge 201 must have, in the cartridge body 202 thereof, the space in addition to the space for accommodating the magnetic disk 205. Therefore, the size of the disk cartridge 201 is enlarged excessively for use as a portable disk.
Another disk cartridge 211 has been disclosed which has a slidable shutter, as shown in FIG. 3, in order to reduce the size thereof.
The disk cartridge 211 has a guide groove formed at an end thereof opposite to the recording/reproducing opening 214 of the cartridge body 212 in the lengthwise direction, the guide groove being formed to permit the shutter 213 to slide. The shutter 213 is made of, for example, an elongated material or metal and formed into an elongated shape. The guide groove is formed adjacent to a magnetic disk 215 accommodated in a disk accommodating portion in order to reduce the size of the disk cartridge.
When the magnetic head is introduced into the disk cartridge 211, the shutter 213 is slid to the side surface of the cartridge body 212, as shown in FIG. 4.
However, the disk cartridge 211 having the structure including the slidable shutter 213 involves generation of dust because the shutter 213 slides and moves in the guide groove. Generated dust adheres to the magnetic disk 215, thus causing the reliability of information signals recorded on the magnetic disk 215 to be improved.
What is worse, the dust generated because of the sliding operation and allowed to adhere to the magnetic disk 215 damages the magnetic head for writing/reading an information signal to and from a signal recording surface of the magnetic disk 215.